Manchester United boss Sir Alex Ferguson accepts they face a battle to keep Cristiano Ronaldo over the long-term.
"That will be the biggest task when he gets to that age.
"How big we are then, in terms of European championships, that will resonate with him and be very, very important to this club.
"That's why I make the point of winning European trophies - we've got to do better at that. And we have got the structure here."